Toxin production by Alternaria alternata in tomatoes and apples stored under various conditions and quantitation of the toxins by high-performance liquid chromatography.
Alternaria alternata strain 8442-3 was inoculated into tomatoes (Lycopersicon esculentum Mill.) and Red Delicious cultivar apples (Malus domestica Borkh.). Half of the lots of each fruit were shrink-wrapped in high-density polyethylene film. Wrapped and unwrapped fruits were incubated under darkness at 4, 15 and 25 degrees C for up to 5 weeks. A high-performance liquid chromatography method was developed to quantitate tenuazonic acid (TeA), alternariol (AOH), alternariol methyl ether (AME), and altenuene (ALT). Shrink-wrapping retarded, but did not completely inhibit growth in tomatoes for 3-7 days. Concentrations of up to 120.6 mg of AOH and 63.7 mg of AME per 100 g of tissue were produced in unwrapped tomatoes stored at 15 degrees C for 4 weeks; 19.0 mg of ALT per 100 g of tomato tissue was produced after 3 weeks at 25 degrees C. AOH, AME and ALT were also produced in unwrapped tomatoes stored at 4 degrees C; however, no TeA was detected in decayed tomatoes, regardless of type of wrapping or storage temperature. Shrink-wrapping resulted in decreased production of AOH, AME, and ALT. Alternaria toxins were not detected in apples stored at 4 and 15 degrees C. The highest concentration of AOH produced (48.8 mg per 100 g of tissue) was in unwrapped apples stored at 25 degrees C for 2 weeks; 12.3 mg per 100 g of tissue of shrink-wrapped apples was detected after 5 weeks of storage at 25 degrees C, while ALT reached 5.7 mg per 100 g after 4 weeks. TeA was not detected in apples infected with A. alternata.
Ozcelik
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Firat Universitesi, Muhendislik Fakultesi, Elazig, Turkey.
Ozcelik
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Beuchat
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D000528:Alternaria / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005516:Food Microbiology; D005519:Food Preservation; D005638:Fruit; D007783:Lactones / Q000032:analysis; D009183:Mycotoxins / Q000032:analysis / Q000096:biosynthesis*; D012997:Solvents; D013696:Temperature; D013720:Tenuazonic Acid / Q000032:analysis / Q000096:biosynthesis
D007783:Lactones; D009183:Mycotoxins; D012997:Solvents; C040005:altenuene; D013720:Tenuazonic Acid; C005197:alternariol